1. Field of the Invention
The present invention relates to integrated circuit processing equipment and, more particularly to atomic layer deposition (ALD) equipment.
2. Description of the Background Art
Semiconductor wafer processing systems that perform atomic layer deposition (ALD) are used to form material layers on high aspect ratio structures. Referring to FIG. 1, ALD systems typically comprise a deposition chamber 10, a gas supply system 12, and a gas exhaust system 14. The deposition chamber includes a pedestal 11 that is used to support a substrate 13 such as a semiconductor wafer. The gas supply system 12 is used to provide reaction gases to the deposition chamber 10, and the gas exhaust system 14 is used to remove reaction gases from the deposition chamber 10.
In ALD processes, a material layer is formed on a substrate by sequentially chemisorbing alternating monolayers of two or more compounds thereon. Each of the alternating monolayers is chemisorbed onto the substrate by providing a different deposition gas to the chamber that comprises one of the two or more compounds used to form the material layer. After each monolayer is chemisorbed on the substrate, a purge gas is introduced into the deposition chamber to flush the deposition gas therefrom.
Since each of the alternating monolayers of the two or more compounds used to form the material layer is chemisorbed onto the substrate by providing a different deposition gas to the chamber followed by a purge gas, atomic layer deposition (ALD) processes are time consuming. As such, integrated circuit fabrication using ALD processes are costly due to decreased wafer throughput.
Therefore, a need exists in the art for atomic layer deposition (ALD) systems for integrated circuit fabrication.